Anti-Human CD34 FITC

The 4H11 monoclonal antibody reacts with human CD34, also known as mucosialin. CD34 belongs
to a protein family which also includes endoglycan and podocalyxin. Members of this family
are single pass transmembrane proteins with a heavily glycosylated extracellular and N-terminal
mucin domain. CD34 was first identified as an antigen expressed on hematopoietic progenitors,
and has since been extensively used as a marker to isolate cells capable of hematopoietic cell
engraftment. In spite of this, the function of CD34 remains unresolved. In addition to expression
on hematopoietic progenitors, CD34 is expressed on some populations of mesenchymal stem cells,
tumor cell lines, and by vascular endothelia in the adult. Epitopes of CD34 have been assigned to
three classes (class I, II or III) based on their differential sensitivity to enzymatic cleavage
by neuraminidase, chymopapain, or O-glycoprotease. According to this analysis, the 4H11 antibody
belongs to class III, indicating that it reacts with a protein epitope.